Holding device for an airplane



March 1l, 1941. R. H. FLEETETAL HULDING DEVICE FOR AN AIRPLANE Original Filed April 24, 1937 Awa M 'Patented Mar. 11, 19411 HOLDING nEvI'cE'Fon'AN l l i Reuben HQFleet, William B. WleatleyQfa-nd' Isaac n 'Y .Y

M. Laddon, San Diego', Calif.

original' application April 24, 1937, serial No.

- 138,844. A Divided and this application Apriilz,r 1938, Seal No.` 1 99,700 .Y

4 claims.

Uur invention relates to the launching of airplanes, and more particularly to the launching of airplanes from moving vehicles. i

This application is a. divison of our co-pendin application Serial No. 138,844, filed April 24, 1937.

Heretofore there have been no efficient means of control of takeoff of an airplane, otherthan the skill of the pilot. l

Often a heavily laden plane will travel down a l field, without rising in the air, a distance greater dii yet

thanit should travel before the brakes are applied. This mistake. in judgment on the .part of the pilot often results in accidents.

An object of the invention is to provide a novel form of hold-back mechanism bywhich the airplane is fastened at a point at the beginningof its run while the motors are being warmed up.

Another object of the invention is to permit the launching of airplanes without human attention, or at least Without skilled handling during the takeoff run until after the plane leaves the vehicle. matic take off is especially valuable for flights controlled by robot pilots.

With these and other )objects in view, which may be incident `to our improvements, the invention consists in the part-s and combinations to be hereinafter set forth and claimed, with the understanding that the severalnecessary elements comprising our invention may be 'varied in construction, proportions 4and arrangement, without departing from the spirit' and scope of the appended claims.`

in order to make our invention more clearlyunderstood, we have shown intheaccompanying 4drawing means for carrying the same into practical eiect without limiting the improvements in their useful applications to the particular conf structions which, for the purpose of explanation, have been made the subject of illustration.

in the drawing:

Figure l is a diagrammatic view of a system employing my invention.

Figure 2 is a View in side elevation .of a seaplane mounted on my supporting vehicle, part of the' 1 supporting vehicle being broken away to show the construction.

Figure 3 is a detail view partly in section of the attachment for the hold-back device wherebyV the airplane is attached to the hold-back cable.

in our system the airplane is held ori the supporting vehicle with its nose held down, so that the airplane is in a substantially no-lift attitude. The elevators may be set to raise the nose of the airplane. 'I'he airplane is held at the end of the In this connection the completely autotrack which supports .the launching` lvehicle byv meansl of va cable.

The motors of the airplane are warmed up and are running full throttle, (or desired power output for takeoff), at whichtime the cable is released,

allowing the motive power or the airplane to move the airplane and the vehicle down the track with increasing. speed. L The center of gravity of the airplane is, in'general, located behind the point of pivoting Vof the cradle on which the airplane l rests. `The airplane is held, however, in the substantially no-lift attitude by reason of hold-down members which are attached to the supporting vehicle. When a proper air speed is reached, the hold-down members for the nose of the airplane are released, and the fact'that the center of gravity of the airplane lies behind the pivot ofl the cradle on which the airplane rests, in addition to the fact that the elevators are set to raise the nose of the airplane, causes the airplane to quickly assume a substantially high angle of attack attitude, and the airplane will then quickly take off from the supporting vehicle.

At a certain point in its run, a trip at the side of the track automatically applies the brakes to the vehicle on which the airplane is supported. The location of this trip may be varied as required. If the airplane has not taken off from the .vehicle when this point is reached,A both airplane and vehicle are thenarrested. However, if the airplane has taken off from the Vehicle, the brakes will stop the vehicle. An arresting cable at the-end of the run prevents overrunning of the vehicle beyond the end of the track.

Referring to the drawing, in Figure 1 we have shown an airplane I mounted on a platform 2 of a vehicle 3.V The vehicle 3 is adapted to travel on tracks I. In Figure 1 the airplane I is shown held by a cable 5 at one end of the track. The motors of the airplane are warmed up, and when they are running at desired power -output the pilot releases the cable 5, as will be later described, and the airplane runs down the track, gaining speed. The elevators of 'thev airplane are set in the position to raise the nose of the airplane. The nose is held down by holding means until the 1 air speed is suflicient for the take off of the air` plane from the vehicle. The section of th' track on which this will normally occur is indicated in r the drawingFigure 1.

If the airplane takes oil before Athe point in Figure 1 where` it is indicated that the car brakes are applied, the vehicle 3 is merely arrested by the application of the brakes, overrunnng being prevented by the arresting gear. y

CFI

We have, indicated the section of track on which'takeoif'usually occurs by the numeral 6, the point at which the car brakes are applied as numeral 1, and the arresting gear to prevent overrunning of the vehicle by the numeral 0.

If suflicient air speed is not attained for the takeoff of the airplane from the vehicle by the time the vehicle reaches the position indicated by the numeral 1, the car brakes are applied and the vehicle, with the airplane on it, is arrested.

Referring to Figure 2, `we have shown the airplane I as a seaplane. It is adapted to be mounted in a cradle 9 which is pivoted on a shaft I0 mounted in supports II which are attached to the surface of the platform 2. On either side of the airplane, and pivoted at points I2 to the upper surface 2 of the vehicle 3, are holding members I3 which areA adapted to hold the nose I4 of the airplane down, as indicated in Figure 2.

In Figure 2 we have shown an elevator j|5 in a normal position. At the beginning of the run the elevator I5 is generally set in a position to raise the nose 4 of the airplane. The center of gravity of the airplane is somewhat back of the pivot shaft I0, tending to raise the nose and lower the tail, but the holding members I3 on either side of the plane prevent this from happening until they are released. Additionally, the setting of the elevators when a substantial forward speed is obtained tends to raise the nose I4.

The hold-down mechanism for holding the airplane in the beginning of the run will now be described. Referring to Figure 1, we have shown that there is a cable 5 which holds the airplane at the beginning of the run until the motors are running full throttle, at which. time the pilot releases the cable 5 from the airplane, and the airplane and the launching vehicle, preferably only under the power of the motive power plant of the airplane, proceed down the rail track l The cable 5 is attached to an anchcr member 300 which may be mounted between the rails of the rail track 4. The cable 5 has a loop 30| which is adapted to pass through an aperture 302 in a male member 303.which is adapted to slide in a slideway 304 formed in a support member 305 which ts within an aperture 306 formed in the bottom` 301 of the fuselage. 'I'he aperture 306 is braced by means of a bracing member 308 which acts as a support for the strain imposed by forces acting through the support member 305.

Pivoted on the support member 305 on a pivot 300 is a fastener 3I0. The fastener 3I0 is provided with a catch 3|| having a sloping surface 3I2 which is adapted to engage a sloping surface 3|3 formed on the end of the male member 303.

A coil spring 3 I4 is adapted to urge the fastener 3I0-in the up, or disengaging, position. The slope of the surfaces 3|2 and 3|3 is such as to tend to move the fastener 3I0 in the up, or disengaged, position. In order to hold the fastener 3| 0 in the down, or engaging, position, there is provided a release member 3I5 which is pivoted on a pivot 3I6 supported by the socket 305. One arm 3| 1 of the release member 3| 5 is adapted to bear against the top of the fastener 3 I 0.

The other arm 3I8 of the release member 3|5 is held in the position indicated in solid lines in Figure 3 by means of a spring 3|9 which is attached to the arm 3| 8 and to the fuselage 301. A cable 320 is pivotally attached at 32| through a suitable connection 322 to the arm 3I8 of the release member 3 I 5.

A stop 323 prevents the spring 3I9 from moving the release member beyond the position shown in solid unes in Figure 3.* Upon the 'pilot pulling" on cable 320, the release member 3|5 is pivoted on its pivot 3|6 against the tension of the spring 3|9 to move the arm 3|`| out of engagement with the top of the fastener 3I0. The fastener 3I0 is raised to the position ,shown in dotted ylines in Figure 3 under the tension of the spring 3I4 and because of the lforces exerted by the engaging surfaces 3I2 and 3I3. The airplane is then freed from the hold-down mechanism and can proceed 10 on its run. j:

In operation, the airplane, with its nose held down in the substantially no-lift attitude, is restin g on the launching vehiclerat the beginning of the run, as indicated in Figure 1. The cable 5 holds the airplane and the supporting vehicle from forward movement while. the engines are being warmed up and until they are running full throttle. The elevators I5 are set to lift the nose of the airplane, but are prevented from functioning until the nose of the airplane is no longer held down by the holding members I3.

When the motor is running full throttle,l or at desired power output, the pilot pulls on cable 220 and releases the airplane and vehicle which,

under the power of the motive power plant of the airplane, runs down the rail tracks 4 until suiiicient air speed is attained for the closing of contacts 10 and 1|.H

The closing of these contacts releases the holding members I3, as previously described, and permits the airplane to rock back on the cradle 9 and to quickly take olf from the launching vehicle. At the same time, cut-out switch 49 is opened to prevent drain on the batteries and overheating of the coils 45.

As the vehicle passes the trip mechanism located at 1 along the track, the brakes are applied and, in case the vehicle is still moving, the arresting cable 8 will stop the vehicle.

If sufficient air speed has not been attained during the run and before the point 1 is reached on the track, the nose of the airplane will be held down in the position indicated in Figure 2 and the airplane cannot take olf from the supporting vehicle.

Thus, automatic lcontrol of takeoff is substituted for the pilots judgment, and safety factors are introduced into the launching of airplanes which have never heretofore been possible.

With our invention no human attention isv required to safely get the aircraft into the air; in fact if a robot pilot such as the Sperry automatic airplane pilot were used on the airplane, no human need even be aboard the aircraft (this might be desirable in time of war in the case of a very dangerous mission where the airplane would be expended to accomplish the mission). Also in time of war, planes `might be launched with our invention, manned by crews not sufficiently skilled to make safe takeoffs in the normal way, yet who could guide t-he plane in flight, and could probably land the plane, which would be much lighter after returning from a mission, without damaging it.

'I'he arrangement of the device to automatically launch an airplane would be such that the relation of the supports and the center of gravity would cause the aircraft to pivot to the takeoif attitude when the forward support was released. With the elevators set for normial climb, or if the automatic (robot) pilot was set for a climbing attitude, then when the forward release was disconnected the plane would automatically take off. l

While we have shown and described the preferred embodiment of `our invention, /we wish it tobe understood that we do not corinne ourselves to the precise details of construction herein set forth by way of illustration, as it is apparent that many changes and variations may be made therein, by those skilled in the art, Without departing from the spirit of the invention, or exceeding the scope of the appended claims. i

We claim: y 1. A hold-back device for an airplane comprising a miale member, a fastener for engaging the male member, a pivoted release member carried by the airplane for locking the fastener in engaging position, the 'release member being aligned inv its locking position with the line of movement of the fastener, the zone of contact between the release member and the fastener extending substantially beyond said locking position in both an inward and an outward direction relative to the line of entry of the male member.

2. `A hold-back device for an airplane comprislng a male member, having a slot therein, a .tension element attached to the male member, a slideway adapted to receive the male member, a fastener for engaging said slot, said fastener being mlovable in a direction perpendicular ,to that of the tension element, said slot and said fastener having slanted cooperating holding surfaces so related to the line of movement of the male member that a pull outward from the .slideway tends to separate the fastener from said slot, a pivoted release member for locking the fastener in engaging position, said pivoted member being aligned in its locking position with the line of movement of the fastener, the zone of contact between said pivoting member and the fastener extending substantially beyond said locking position in both an inward and an outward direction relative to the line of entry'lof the male member.

3.v A hold-baci;l device for an airplaney comprising a tension element, a member attached to the tension element, a slideway carried by the airplane for slidably receiving the member, mieans carried by the airplane for laterally engaging the member, a pivoted release adapted to hold the engaging means in engaged position, link means adapted to be operated by the pilot for moving the release to permit the engaging means to release the member, and a spring carried by the -release tending to hold the release .in its engaging position, the member and the prising a support member having a slideway` therein, a male member slidable in the slideway, the male member having engaging surfaces laterally engageable, a fastener carried by the support member and having fastening surfaces for locking the male member in position against one surface of the slideway, said engaging surfaces on the male member when in locked position lying completely outside the path of said fastening surfaces from free to llockingy position, whereby the male miember may be placed in the slideway to the proper depth and locked in position without further movement of the male member, a release member pivotally carried by thesupport member and having an arm presenting an area of. contact with the fastener, said fastener-contacting area being adapted to contact a portion of the fastener when any strain on the release member from the fastener is substantially on a line between the fastener and the pivot of the release member, whereby the fastener is held in locking position, means to pivot the release member into strain-aligning REUBEN H. EIEET. WILLIAM B. WHEA'ILEY. ISAAC M. LADDoN. 

